4. (From HWH4) Gasoline (predominantly 90% Octane (C8H18) and 10% ethanol) is burned completely with 30% excess air to form CO2 and H2O. At STP, the density of octane is 6.15mol/L and that of ethanol is 17.12mol/L. Determine the gross and net heating value of this fuel. First table givi NIST website. The : table gives average Cp values in J/molC. Use heat of vaporization of water as 40.8kJ/mol. (Hint: watch "Combustion reaction.mp4"). Also, you could use the material balance from HW \#4